Sealing device

Abstract

A sealing device includes a seal lip located inside a hole of an outer member and in slidable contact with the inner member. The seal lip has an inclined surface arranged on a side of the internal space, an atmosphere-side inclined surface, and a lip edge on a boundary between the inclined surfaces. Multiple first helical ribs and multiple second helical ribs extending from the lip edge and in contact with the outer peripheral surface of the inner member are formed on the atmosphere-side inclined surface. In addition, multiple first dike ribs and multiple second dike ribs are formed on the atmosphere-side inclined surface, which are arranged away from the lip edge and are not in contact with the inner member. The first dike ribs are arranged to intersect the extended lines of the first helical ribs, respectively, and are inclined in the opposite direction to the first helical ribs. The second dike ribs are arranged to intersect the extended lines of the second helical ribs, respectively, and are inclined in the opposite direction to the second helical ribs.

1 . A sealing device, disposed between an inner member and an outer member that rotate relative to each other, for sealing a gap between the inner member and the outer member, the sealing device comprising:
 a mounted part to be mounted on the outer member; and   a seal lip located inside a hole of the outer member, the seal lip being in slidable contact with an outer peripheral surface of the inner member for separating the internal space of the outer member from an atmosphere side to seal liquid within the internal space,   the seal lip comprising a liquid-side inclined surface arranged on a side of the internal space, an atmosphere-side inclined surface arranged on an atmosphere side, and a lip edge on a boundary between the liquid-side inclined surface and the atmosphere-side inclined surface and extending in a circumferential direction,   the liquid-side inclined surface being inclined such that the more distant it is from the lip edge, the more distant it is from the inner member,   the atmosphere-side inclined surface being inclined such that the more distant it is from the lip edge, the more distant it is from the inner member,   multiple first helical ribs and multiple second helical ribs being formed on the atmosphere-side inclined surface, the first helical ribs extending from the lip edge and being in contact with the outer peripheral surface of the inner member, the second helical ribs extending from the lip edge and being in contact with the outer peripheral surface of the inner member,   the multiple first helical ribs extending helically at an angle to the lip edge, the multiple second helical ribs extending helically at an angle to the lip edge in directions opposite to directions of the first helical ribs,   multiple first dike ribs and multiple second dike ribs being formed on the atmosphere-side inclined surface, the first dike ribs being arranged away from the lip edge and being not in contact with the outer peripheral surface of the inner member, the second dike ribs being arranged away from the lip edge and being not in contact with the outer peripheral surface of the inner member,   the multiple first dike ribs being arranged to intersect with extended lines of the multiple first helical ribs, respectively, and extending helically at an angle in directions opposite to directions of the first helical ribs, the multiple second dike ribs being arranged to intersect extended lines of the multiple second helical ribs, respectively, and extending helically at an angle in directions opposite to directions of the second helical ribs.   
     
     
         2 . The sealing device according to  claim 1 , wherein the multiple first dike ribs comprise a first end dike rib that is closest to the multiple second dike ribs among the multiple first dike ribs, the first end dike rib having a lip-edge-side end that is closer to the lip edge than atmosphere-side ends of the multiple first helical ribs, the first end dike rib having an atmosphere-side end that is more distant from the lip edge than atmosphere-side ends of the multiple first helical ribs, and
 wherein the multiple second dike ribs comprising a second end dike rib that is closest to the multiple first dike ribs among the multiple second dike ribs, the second end dike rib having a lip-edge-side end that is closer to the lip edge than atmosphere-side ends of the multiple second helical ribs, the second end dike rib having an atmosphere-side end that is more distant from the lip edge than atmosphere-side ends of the multiple second helical ribs.   
     
     
         3 . The sealing device according to  claim 1 , wherein lip-edge-side ends and atmosphere-side ends of at least some first dike ribs among the multiple first dike ribs are more distant from the lip edge than atmosphere-side ends of the multiple first helical ribs, and
 wherein lip-edge-side ends and atmosphere-side ends of at least some second dike ribs among the multiple second dike ribs are more distant from the lip edge than atmosphere-side ends of the multiple second helical ribs.   
     
     
         4 . The sealing device according to  claim 2 , wherein lip-edge-side ends and atmosphere-side ends of at least some first dike ribs among the multiple first dike ribs are more distant from the lip edge than atmosphere-side ends of the multiple first helical ribs, and
 wherein lip-edge-side ends and atmosphere-side ends of at least some second dike ribs among the multiple second dike ribs are more distant from the lip edge than atmosphere-side ends of the multiple second helical ribs.